The present invention relates to a workpiece attaching and detaching apparatus for use in a transfer type working apparatus. Transfer type working apparatuses convey a workpiece along a conveying line so that it may be successively worked upon by one or more working tools disposed along the line. The workpiece is generally mounted on a pallet. The workpiece is attached to the pallet at the beginning of the line, by a fastening means provided on the pallet. At the terminal end of the line, the workpiece is detached by unfastening the fastening means. The present invention is provided for attaching and detaching the workpiece.
It has been usual with this kind of apparatus that a transfer means for effecting a transfer of a workpiece between a first station for the pallet to be charged or discharged and a second station for the workpiece to be charged or discharged, and a fastening-and-unfastening means for the fastening means provided on the pallet are provided separately one from another. When the workpiece is intended to be attached to the pallet, the workpiece may be transferred by the transfer means from the second station to the pallet at the first station. Thereafter the fastening-and-unfastening means is moved from its stand-by position to its operative position located opposite to the first station for effecting the fastening operation. When the workpiece is intended to be detached from the pallet, and fastening means is unfastened by the fastening-and-unfastening means at the first station. Thereafter the workpiece unfastened and resting on the pallet is transferred to the second station by the transfer means. This conventional type apparatus, however, has various inconveniences as described below.
(i) For preventions of mutual operative interference between the transfer means and the fastening-and-unfastening means, it is necessary that before the fastening-and-unfastening means is operated for attaching the workpiece to the pallet, the transfer means is retreated towards the second station. Thus, a waiting time for the retreating operation of the transfer means is needed. Consequently, there is caused a lowering in working efficiency by the waiting time.
(ii) When the workpiece to be attached or detached is changed from one type to a different type which is different from the other in respective engageable positions to be engaged for fastening, by the respective fastening members, it is necessary that the old fastening-and-unfastening means be removed from the attaching and detaching apparatus and in place thereof a new one corresponding to the new workpiece is attached thereto. Thus, the operation of replacing thereof is troublesome.